Modern GPS and other position determination techniques, communications, and information processing have enabled sophisticated position tracking systems.
For example, Thomas (U.S. Pat. No. 7,366,522) discloses a position monitoring system that displays position information via a web server.
Some tracking systems use the technique of geofencing.
Geofencing is the establishment of a predetermined boundary such that different actions are taken depending on whether a position is determined to be inside or outside of the boundary.
Jones (US patent application 2001/0052849) discloses a system that notifies a server if a stored boundary rule set is breached.
Tracking systems and geofencing are useful for a variety of purposes. Most systems relate to security applications or logistics but there is also a need for tracking and geofencing for safety purposes.
In addition, existing geofencing applications classify zones in a binary (allowed/excluded) fashion which is unsuitable for an application tracking assets that may be off duty, in transit or at a work site and for which different treatment is required for each kind of area.